High Precision CO2 Sensor for Balloon Sonde Atmospheric Measurements

72037S03-I A better scientific understanding of the sources and sinks of CO2, and of the interactions between the biosphere and atmosphere (troposphere and stratosphere) are needed. However, in situ measurements have been restricted to airplane or large stratospheric-type balloon gondola platforms, due to the size, weight, and power requirements of current instrumentation. A more frequent, widespread measurement campaign using smaller, less expensive balloon sondes is limited by the lack of suitable instrumentation. This project will develop a simple, lightweight, inexpensive carbon dioxide sensor suitable for balloon sonde measurements, yet exhibiting specifications that match the much larger and expensive research instruments used on current airborne platforms. Phase I will determine the best technical approach, using optical absorption to achieve high precision over the range of severe environmental conditions expected. In addition, calibration issues under the severe restrictions of balloon sonde flight will be addressed. The Phase II product will be a sensor capable of measuring sub-ppmv (part-per-million by volume) fluctuations of CO2 using simple balloon sondes without the need for highly trained personnel. Commercial Applications and Other Benefits as described by awardee: In addition to its use as a research instrument for atmospheric measurements, a low cost, portable gas sensor should have application in such areas as gas leak sensing of pipelines, fire detectors for commercial and private aircraft, and process control sensors for energy and chemical production industries.